//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// <unordered_map>

// template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
//           class Alloc = allocator<pair<const Key, T>>>
// class unordered_multimap

// void reserve(size_type n);

#include <unordered_map>
#include <string>
#include <set>
#include <cassert>

#include "test_macros.h"
#include "min_allocator.h"

template <class C>
void test(const C& c) {
  assert(c.size() == 6);
  {
    std::set<std::string> s;
    s.insert("one");
    s.insert("four");
    assert(s.find(c.find(1)->second) != s.end());
    s.erase(s.find(c.find(1)->second));
    assert(s.find(std::next(c.find(1))->second) != s.end());
  }
  {
    std::set<std::string> s;
    s.insert("two");
    s.insert("four");
    assert(s.find(c.find(2)->second) != s.end());
    s.erase(s.find(c.find(2)->second));
    assert(s.find(std::next(c.find(2))->second) != s.end());
  }
  assert(c.find(3)->second == "three");
  assert(c.find(4)->second == "four");
}

void reserve_invariant(std::size_t n) // LWG #2156
{
  for (std::size_t i = 0; i < n; ++i) {
    std::unordered_multimap<std::size_t, size_t> c;
    c.reserve(n);
    std::size_t buckets = c.bucket_count();
    for (std::size_t j = 0; j < i; ++j) {
      c.insert(std::unordered_multimap<std::size_t, size_t>::value_type(i, i));
      assert(buckets == c.bucket_count());
    }
  }
}

int main(int, char**) {
  {
    typedef std::unordered_multimap<int, std::string> C;
    typedef std::pair<int, std::string> P;
    P a[] = {
        P(1, "one"),
        P(2, "two"),
        P(3, "three"),
        P(4, "four"),
        P(1, "four"),
        P(2, "four"),
    };
    C c(a, a + sizeof(a) / sizeof(a[0]));
    test(c);
    assert(c.bucket_count() >= 7);
    c.reserve(3);
    LIBCPP_ASSERT(c.bucket_count() == 7);
    test(c);
    c.max_load_factor(2);
    c.reserve(3);
    LIBCPP_ASSERT(c.bucket_count() == 3);
    test(c);
    c.reserve(31);
    assert(c.bucket_count() >= 16);
    test(c);
  }
#if TEST_STD_VER >= 11
  {
    typedef std::unordered_multimap<int,
                                    std::string,
                                    std::hash<int>,
                                    std::equal_to<int>,
                                    min_allocator<std::pair<const int, std::string>>>
        C;
    typedef std::pair<int, std::string> P;
    P a[] = {
        P(1, "one"),
        P(2, "two"),
        P(3, "three"),
        P(4, "four"),
        P(1, "four"),
        P(2, "four"),
    };
    C c(a, a + sizeof(a) / sizeof(a[0]));
    test(c);
    assert(c.bucket_count() >= 7);
    c.reserve(3);
    LIBCPP_ASSERT(c.bucket_count() == 7);
    test(c);
    c.max_load_factor(2);
    c.reserve(3);
    LIBCPP_ASSERT(c.bucket_count() == 3);
    test(c);
    c.reserve(31);
    assert(c.bucket_count() >= 16);
    test(c);
  }
#endif
  reserve_invariant(20);

  return 0;
}
